Add two spare fields to struct resource for some planned enhacenments

to make it possible to merge them w/o changing the size of struct resource
which some drivers unfortunately still need to know.

sys/sys/rman.h

@@ -107,6 +107,8 @@ struct resource {
 	bus_space_handle_t r_bushandle;	/* bus_space handle */
 	struct	device *r_dev;	/* device which has allocated this resource */
 	struct	rman *r_rm;	/* resource manager from whence this came */
+	void    *r_spare1;	/* Spare pointer 1 */
+	void    *r_spare2;	/* Spare pointer 2 */
 	int	r_rid;		/* optional rid for this resource. */
 };
 #else